The difference between unmatched rev3 and rev1 is DDR timing, the rev3 uses 1866 MT/s for 16GiB, and rev1 uses 2133 MT/s for 8GiB. Signed-off-by: Zong Li <zong.li@sifive.com> Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>